1. Field of the Invention
This invention relates to a florescence endoscope apparatus for capturing: a white light image that is used for acquiring information on the shape of an object to be observed, like a living body for example; and plural types of fluorescence images that are used for acquiring information on a degenerate site of the object to be observed, such as a lesion in a living body.
2. Description of Related Art
As a conventional fluorescence endoscope apparatus for capturing plural types of fluorescence images and a white light image while a decrease in a frame rate for white light image showing information on shape with one observation mode is being controlled to the small extent to the utmost, a fluorescence endoscope apparatus disclosed in Japanese Patent Kokai No. 2011-188929 has been suggested for example.
FIGS. 1A-1C are explanatory views showing one example of structures for the fluorescence endoscope apparatus disclosed in Japanese Patent Kokai No. 2011-188929. To be specific, FIG. 1A is a block diagram conceptually showing its whole structure, FIG. 1B is a view showing a configuration of respective transmittal portions of a rotary filter that is provided for a light source unit for the apparatus shown in FIG. 1A, and FIG. 1C is a timing chart conceptually showing timing with which a white light image and plural types of fluorescence images are captured in the fluorescence endoscope apparatus disclosed in Japanese Patent Kokai No. 2011-188929.
The fluorescence endoscope apparatus shown in FIGS. 1A-1C include a light source unit 51, an image pickup unit 52, and an image processing unit 54. In FIG. 1A, the numeral reference 53 denotes a light-guiding means like a light guide, the numeral reference 54a denotes a frame memory, the numeral reference 55 denotes an image-displaying apparatus, and the numeral reference 56 denotes an insertion unit of the front end of the endoscope.
The light source unit 51 includes a light source 51a and a rotary filter 51b. The light source 51a emits light containing: white light for observing the shape of an object 59 to be observed; and plural types of exciting light for exciting plural types of fluorescent substances that exist in the object 59. The rotary filter 51b is provided with: white light-transmitting portions 51b2 and 51b4 that transmit white light of light emitting from the light source 51a; and plural types of exciting light-transmitting portions 51b1 and 51b3 that transmit plural types of exciting light respectively of light emitting from the light source 51a, with these transmittal portions 51b1, 51b2, 51b3, and 51b4 located in the same circumferential direction.
The image pickup unit 52 and the image-processing unit 54 are formed to operate respectively in such a way that: the image pickup unit 52 receives while light reflected by an object 59 to be observed and plural types of fluorescence emitted from an aggregation 59a of fluorescent substances in the object 59; and the image-processing unit 54 outputs one frame of a white light image, one frame of the first fluorescence image, one frame of the white light image, and one frame of the second fluorescence image in chronological order every one rotation of the rotary filter 51b so that an output of the white light image is inserted between outputs of respective fluorescence images, with the result that a frame rate for the white light image is larger than frame rates for the respective fluorescence images.